GLENDALE, Ariz  The Chargers expressed a measure of relief after Saturday night’s uneven victory over the Arizona Cardinals.

And that feeling had virtually nothing to do with the 90-yard touchdown drive led by backup quarterback Billy Volek, completed with a 14-yard touchdown reception by Bryan Walters with three seconds remaining, to give the Chargers a 34-31 victory.

“Really, I think it was good for us to not have it go so smooth,” Philip Rivers said afterward. “Obviously, we did some things we’ve got to do better. If everything had gone perfect in this game, we would have floated into that first (regular season) game, kind of. Now it will really make everybody (know) we’ve got to bear down. It’s perfect.”

Against an Arizona defense moving all over and bringing pressure in varied ways much of the night as it works on instituting a new defense with a new coordinator, the Chargers’ offense worked through fits and starts before moving the ball at a decent pace through most of the time the starters remained in the game.

“I thought we bounced back pretty good,” Rivers said. “… We saw a lot. This is going to be a great tape to learn from. We saw every blitz in the book. We saw this, we saw that. We did a little more because we were in there longer … It will be a good one to look at.”

And against a Cardinals offense led by newly acquired quarterback Kevin Kolb, a Chargers defense minus injured Antonio Garay, Larry English and Shaun Phillips got run over and run around enough that there will be plenty to work on before the Sept. 11 season opener.

After playing a bunch of man coverage and making play after play six days prior in Dallas, the defense sat back in an almost neutral posture compared to the first two preseason games. Whether it was new Chargers coordinator Greg Manusky dialing it back on purpose for some sort of learning reasons, the Chargers nonetheless got beat at the line and down the field early.

Kolb completed just 11 of his 20 passes but for 205 yards and a touchdown. Worse, the Cardinals ran 16 times for 125 yards in the first three quarters.

“We’re still learning,” safety Eric Weddle said. “It’s good to hit some adversity early on. It’s been, I wouldn’t say easy, but we’ve been playing well. But to not play well and come back and go get a stop shows we have some character. We’re still learning each other.

“We’re behind. We’ve got to realize there’s still a long way to go … We’ve got to shore it up, and we will. That’s why it’s preseason. You work on some things, you figure out what you’re not so good at and you go fix it.”

For the Chargers, whose running game is continuously under scrutiny, Ryan Mathews’ 48-yard sprint up the middle in the third quarter was just the fourth run longer than 2 yards in 15 attempts to that point. The Chargers finished three quarters with 98 yards on 18 carries.

“It’s more like a regular season game when you get in (the third preseason) game,” Norv Turner said. “They gave us some looks they haven’t shown in the last two games, so you’re trying to get work on the different looks and trying to get the running game going. It’s hard to evaluate your running game until you get to go for four quarters. I thought we had some good runs, and we had some breakdowns in the running game. A couple plays we’re one guy away from getting a real big play.”

One thing that is apparent after he made his first start of the preseason is that defensive end Corey Liuget, the Chargers’ first-round pick, can create havoc no matter who he’s going against. He was quick and strong off the line against other first-teamers and then in the fourth quarter got in the backfield to disrupt a handoff that was fumbled and recovered in the end zone by Darryl Gamble to pull the Chargers to within four points.

“It definitely helped me step toward where I need to be at, as far as playing with the ones and rotating and getting a feel for the game on an NFL level,” Liuget said. “… It showed me I can definitely play on this level."

Down by two touchdowns after the Cardinals scored on big plays within 99 seconds of each other — an 80-yard Larry Fitzgerald touchdown and a 34-yard interception return by Patrick Peterson — the Chargers marched down the field for their first touchdown of the night. The final two plays came on completions to Rivers’ favorite targets — a 31-yard catch and run by Vincent Jackson and then a 13-yard pass to Antonio Gates as he ran out of the end zone.

A 70-yard drive at the end of the first half — during which, after a 10-yard holding penalty to start, Rivers was 7-for-9 for 73 yards, including a three-yard touchdown pass to Malcom Floyd — brought the Chargers to 24-17.

Rivers, who was not sacked but got hit repeatedly and was under duress when he was intercepted, finished 18-for-28 for 198 yards and two touchdowns.

Mathews’ big run started off the Chargers’ second possession of the second half with promise, but what would be Rivers’ final drive ended with a 36-yard Nate Kaeding field goal that made it 24-20.

Mostly substitutes populated the game thereafter, and the Cardinals drove 80 yards for a touchdown that gave them a 31-20 lead 2½ minutes into the fourth quarter.

On the final drive, which began with 3:11 remaining, Volek completed five of his 10 passes for 69 yards. His final two completions were a 27-yarder to Walters and the winning pass from the 14 to Walters just inside the end zone.

“It was obviously a wild game,” Turner said. “We gave up a couple big plays early. We dug ourselves a hole. But I liked the way our guys handled it on the sideline, and I liked the way we responded, getting it to a one-touchdown game at the half. And the young guys at the end of the game, I liked they finished the game and found a way to go win.”